(C) Andryashkin A., Ulyanovsk
reg., r.p.Staraya Maina
I fully agree with the opinion
that before you send the log their procedures, you should first
optimize them in terms of or speed.
Here, for example, the procedure
Alexander Soloviev (ZX REVIEW
N5/1995 str.51) to indicate
amplitude channels of music
coprocessor, which he occupies 70 bytes. If it hold
unpretentious permutation (Remove unneeded routines) and
replace operations on shorter, you can shorten it to
10 - 15 bytes, but in my opinion, it is possible to go further.
140.
ANAL LD HL, # 58E2
LD A, 3
AN1 PUSH AF
LD HL, # FFFD
ADD A, 7
OUT (C), A
IN A, (C)
PUSH HL
LD C, 4
AN2 LD B, 4
AN3 DEC H
DEC H
OR A
LD (HL), A
JR Z, AN4
LD (HL), 126
DEC A
AN4 DJNZ AN3
LD DE, # 07E0
ADD HL, DE
DEC C
JR NZ, AN2
POP HL
POP AF
DEC L
DEC A
JR NZ, AN1
RET
2
This procedure will work
in any third of the screen (the address of the indicator 3
channel recorded in the HL [Label ANAL]).
I take this opportunity to recall the same unpretentious
design, if you want to take away from the register pair HL any
number (constant), then usually uses the following
Design:
LD DE, NN
AND A; because unknown state carry flag
SBC HL, DE
But this construction can be shortened to 2 bytes (not to
mention speed of execution), if instead of subtracting using
addition and constant overeat in the extra code:
LD DE ,0-NN
ADD HL, DE
Since the digital technology holds the subtraction operation.
*
